Indicator for bascules



I T. E. BROWN, JR

INDICATOR FOR BASCULES Filed June 1927 5 Sheets-Sheet 1 Jan. 29, 1929. 1,700,464

1'. E. BROWN. JR

INDICATOR FOR BASCULES Filed June 1. 1921 :s Sheets-Sheet 2 3 Sheets-Sheet T. E. BROWN, JR

lNJJICATOR FOR BASGULES Filed June 1, 1927 SE -R141 flag Jan. 29, 1929.

Patented Jan. 29, 1929.

UNITED STATES THOMAS E. BROWN, J 3., OF YONKERS, NEW YORK.

INDICATOR FOR BASGULES.

Application filed June 1,

This invention relates to bridges and aims to provide means for indicating the position of a movable part of the bridge.

While not'limited thereto the embodiment of the invention illustrated is particularly adapted for use in connection with bascule bridges such as those operated by a pinion and rack strut; and includes a pointer operatively connected with bascule power transn'lission mechanism in such manner that the pointer moves at the same angular rate as the bascule, so that the pointer always occupies an angular position corresponding to the angular position of the bascule.

The invention will be apparent from the following specification when read in connection with the accompanying drawing in which Fig. l is a side elevation of a bascule bridge equipped with my improved indicator;

Fig. 2 is an enlarged detail of the indicator;

Fig. 3 is an enlarged detail of a portion of the bridge showing the control house and indicator located therein;

Fig. 4 is a plan of Fig. 3 with parts in horizontal section;

Fig. 5 is a detail view showing the operative connection between the bascule operating mechanism and the indicator;

Fig. 6 is a view from the left of Fig. 5;

Fig. 7 is a detail section on line 77 of Fig. 5;

8 is a diagrammatic view of a modification.

Referring in detail to the drawings the bridge illustrated includes a bascule 1O adapted to be swung about a substantially horizontal pivotal axis 12 by means of a pair of rack struts 14 44 which are pivoted at 16 to each side of the bascule. The rack struts 14 mesh with pinions 18 secured to shafts 20. Each shaft 20 also carries a gear 22 which meshes with a pinion 24 carried by a cross shaft 26 which in turn is driven through suitable reduction gearing of known arrangement by the motors 30. p

The bascule is counterbalanced by a weight 32 carried by a balance beam 34 pivoted at 36 to the stiff leg truss 38, the beam 34 being connected ateach side to the bascule by a hanger link 40 and a span pin 42.

The motors and transmission mechanism elements described are capable of swinging the bascule from the full line position of Fig. 1 to a position slightly beyond the dotted posi- 1927. Serial No. 195,656.

tion. It is important that the operator should at all times know correctly the position of the bascule leaf, to prevent over-running or undue shock in seating and to permit of proper clearance for different sized vessels and so forth. I

The operating mechanism is located in a house 44 above the center of the roadway, and the bridge tonders or operators house 46 is located at one side of the bridge ata level lower than the machinery house 44.

The house 46 has windows facing the bascule but its position is of necessity so located that the operator cannot accurately determine the angular movement of the bascule by observation.

' To guard against the possibility of accident due to the bascule being moved beyond a predeterminedupright position, I provide an indicator in the house 46 which moves at the same angular rate at which the bascule moves. This indicator in the embodiment illustrated in F igs. 1 to 7 includes a pointer 48 secured to a stub shaft 50 which carries an arm 52 having a sheave 54 mounted on the free end thereof. This arm carries av weight Silwhich tends to move the pointer toward the horizontal position shown in full line in F ig'. 2.

For moving the pointer atthe same angular rate as the bascule, I provide a drum 58 of predetern'iined diameter which is secured to the shaft 20. One end of a cable 60 is made fast to this drum. The cable passes through a tube 62 to a guide sheave 64, thence through a second tube (56 and over guide sheaves 68 and 7d thence around sheave 54 carried by arm 52 and over guide sheave 72 to a takc-up device preferably a turn-buchle74 which is anchored at 76 to a fixed pin or other suitable fixed member. The shaft 50 which carries the pointer 48 and arm 52 is journalled in a panel board 78 having a scale 80 which is calibrated in degrees. This-panel is provided with feet 82 which are secured to the wall 84 of the ,operators house facing the bascule. The controller 86 for the motors 80 is conveniently located in front of a window 88 at the left of the indicator. Thus the operator can watch the movement of the bascule and glance also at the indicator.

The diameter of the drum 58 and the length of arm 52 is such that the pointer moves at the same angular rateas the bascule hence when the motors are moving the bascule, the pointer will indicate the corresponding successive angular positions thereof.

In Fig. 8 I have illustrated a modification in which the indicator includes a pointer pivoted at 92 on a panel 94. The pointer carries an arm 95 to one end of which is pivoted a rack 96 which meshes a pinion 98 on a shaft 100 which also carries a sprocket 102. A chain 104 connects with a sprocket 106 on the cross shaft 20 which drives the pinions 18 for actuating the bascule operating rack struts 14.

It is clear that the angular motions of the bascule leaf 10 and the operating pinion 18 have a constantly varying ratio to each other. Any indicating pointer therefore with a constant gear ratio to pinion 18 will not move in true relation to the motion of the bascule leaf. I, therefore introduce on a miniature scale between pinion 18 and the pointer of the indi cator, a mechanical motion which reproduces the motion of the operating mechanism.

In the arrangement shown in Fig. 2, this similar mechanical motion is comprised of the stub shaft 50, the arm 52, the sheaves 70 and 54, and the portion of the cable 60 con necting said sheaves. These correspond respectively with the axis 12, the end post of the bascule (i. e. the part between points 12 and 16) pinion 1.8, pivotal point 16, and the rack strut 14.. The diameter of drum 58 and the location of sheave 70 with respect to shaft 50 and arm 52, are so chosen as to cause the line which joins the centers of sheaves 70 and 54 and arm 52 to have the same motions as the rack strut 14 and the end post of the span. Arm 52 and pointer 48 will therefore always have the same angular motion as that of the bascule.

Many modifications of my device he made without departing from the spirit of the invention. For example, in Fig. 2, sheaves 7 2 and 54 can be dispensed with a rope 60 attached directly to the end of arm 52. In such case sheave 70 would be placed in the same position, relative to shaft 50 and arm 52, that pinion 18 is located in relation to axis 12 and the end post of the bascule. The diameters of drum and sheave 70 would be varied to suit. I prefer, however, the multiplying sheave arrangement I have shown in Fig. 2 as permitting of any convenient location of the adjusting turn-buckle 7 4 and of a more convenient size of drum 58.

In Fig. 8, I have shown diagrammatically a modification in which the miniature reproduction of the bridge actuating mechanical motion is more readily seen. A miniature pinion 98 is connected to the shaft 20 by any convenient mechanical drive such as sprocket wheels 102 and 106 and sprocket chain 104. Pinion 98 in turn reciprocates rack 96, thereby oscillating arm 95 about shaft 92. It is clear that if the size and arrangement of this miniature mechanism be made in exact proportion to the operating mechanism of the bascule, the arm 95 together with pointer90 will move in synchronism with the bascule leaf 10.

While I have described my invention with particular reference to the embodiment illustrated, it is not to be construed that I am limited thereto since various changes may be made within the scope of the appended claims.

What I claim is 1. In combination with a bascule bridge a motor and power transmission mechanism arranged to swing the bascule about a substantially horizontal axis, a graduated scale, a pointer swingable in juxtaposition thereto, a drum turned by said mechanism, a flexible cable having one end secured to said drum, a pivoted arm carrying a sheave at its free end, said cable passing around said sheave and having its other end fastened to a fixed support, said pointer being movable with said arm and adapted to indicate the angular movement of the bascule.

2. In combination with a bascule bridge a motor and power transmission mechanism arranged to swing the bascule about a substantially horizontal axis, a graduated scale, a pointer swingable in juxtaposition thereto, a drum turned by said mechanism, said pointer being adapted to indicate the extent of movement of the bascule and means ineluding a flexible transmission element having an end secured to said drum arranged to move said pointer in synchronism with the movement of said bascule.

8. An indicator of the class described comprising a pivoted pointer, a pointer actuating drum having one end of a cable fastened.

thereto, a sheave operatively connected to said pointer and around which said cable passes, a member to which the other end of said cable is fastened and means tending to swing the pointer in one direction.

4. An indicator of the class described comprising a pivoted pointer, a counterweighted arm movable therewith, a rotary drum having one end of a cable fastened thereto, a sheave carried by the free end of said arm around which the cable passes, fixed guide sheaves and a fixed anchorage for the other end of said cable, and a graduated scale juxtaposed to said pointer.

5. In combination with a bascule bridge and a pinion and rack strut for moving the bascule, an indicator including a pointer and motion transmission mechanism operatively connected with said pinion arranged to reproduce the angular motion of the rack strut and the bascule.

6. In combination with a bascule bridge a rack strut and pinion for swinging the bascule leaf, an indicator including a pointer swingable in an arc, and motion transmission mechanism between the pinion and said pointer arranged to reproduce the motion of the rack strut so as to move the pointer to successive angular positions corresponding to the angular positions to which the loaseule is moved.

7 In combination With a bascule bridge, a motor driven pinion and rack strut arranged to swing the bascule about a substantially horizontal axis at a variable angular'rate, a graduated scale, a pointer sWingable in juxtaposition thereto and motion transmission mechanism between said pointer and said pin- 10 ion comprising devices similar to the rack strut and bascule arranged to move the pointer to successive positions corresponding exactly to the angular positions to Which the bascule is moved.

In Witness whereof, I have hereunto signed my name.

' THOMAS E. BROWN, JR. 

